<?php
/*
 *  $Id: Query.php 7490 2010-03-29 19:53:27Z jwage $
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * This software consists of voluntary contributions made by many individuals
 * and is licensed under the LGPL. For more information, see
 * <http://www.doctrine-project.org>.
 */

/**
 * Doctrine_Query
 * A Doctrine_Query object represents a DQL query. It is used to query databases for
 * data in an object-oriented fashion. A DQL query understands relations and inheritance
 * and is dbms independant.
 *
 * @package     Doctrine
 * @subpackage  Query
 * @license     http://www.opensource.org/licenses/lgpl-license.php LGPL
 * @link        www.doctrine-project.org
 * @since       1.0
 * @version     $Revision: 7490 $
 * @author      Konsta Vesterinen <kvesteri@cc.hut.fi>
 * @todo        Proposal: This class does far too much. It should have only 1 task: Collecting
 *              the DQL query parts and the query parameters (the query state and caching options/methods
 *              can remain here, too).
 *              The actual SQL construction could be done by a separate object (Doctrine_Query_SqlBuilder?)
 *              whose task it is to convert DQL into SQL.
 *              Furthermore the SqlBuilder? can then use other objects (Doctrine_Query_Tokenizer?),
 *              (Doctrine_Query_Parser(s)?) to accomplish his work. Doctrine_Query does not need
 *              to know the tokenizer/parsers. There could be extending
 *              implementations of SqlBuilder? that cover the specific SQL dialects.
 *              This would release Doctrine_Connection and the Doctrine_Connection_xxx classes
 *              from this tedious task.
 *              This would also largely reduce the currently huge interface of Doctrine_Query(_Abstract)
 *              and better hide all these transformation internals from the public Query API.
 *
 * @internal    The lifecycle of a Query object is the following:
 *              After construction the query object is empty. Through using the fluent
 *              query interface the user fills the query object with DQL parts and query parameters.
 *              These get collected in {@link $_dqlParts} and {@link $_params}, respectively.
 *              When the query is executed the first time, or when {@link getSqlQuery()}
 *              is called the first time, the collected DQL parts get parsed and the resulting
 *              connection-driver specific SQL is generated. The generated SQL parts are
 *              stored in {@link $_sqlParts} and the final resulting SQL query is stored in
 *              {@link $_sql}.
 */
class Doctrine_Query extends Doctrine_Query_Abstract implements Countable
{
	/**
	 * @var array  The DQL keywords.
	 */
	protected static $_keywords  = array('ALL',
                                         'AND',
                                         'ANY',
                                         'AS',
                                         'ASC',
                                         'AVG',
                                         'BETWEEN',
                                         'BIT_LENGTH',
                                         'BY',
                                         'CHARACTER_LENGTH',
                                         'CHAR_LENGTH',
                                         'CURRENT_DATE',
                                         'CURRENT_TIME',
                                         'CURRENT_TIMESTAMP',
                                         'DELETE',
                                         'DESC',
                                         'DISTINCT',
                                         'EMPTY',
                                         'EXISTS',
                                         'FALSE',
                                         'FETCH',
                                         'FROM',
                                         'GROUP',
                                         'HAVING',
                                         'IN',
                                         'INDEXBY',
                                         'INNER',
                                         'IS',
                                         'JOIN',
                                         'LEFT',
                                         'LIKE',
                                         'LOWER',
                                         'MEMBER',
                                         'MOD',
                                         'NEW',
                                         'NOT',
                                         'NULL',
                                         'OBJECT',
                                         'OF',
                                         'OR',
                                         'ORDER',
                                         'OUTER',
                                         'POSITION',
                                         'SELECT',
                                         'SOME',
                                         'TRIM',
                                         'TRUE',
                                         'UNKNOWN',
                                         'UPDATE',
                                         'WHERE');

	/**
	 * @var array
	 */
	protected $_subqueryAliases = array();

	/**
	 * @var array $_aggregateAliasMap       an array containing all aggregate aliases, keys as dql aliases
	 *                                      and values as sql aliases
	 */
	protected $_aggregateAliasMap      = array();

	/**
	 * @var array
	 */
	protected $_pendingAggregates = array();

	/**
	 * @param boolean $needsSubquery
	 */
	protected $_needsSubquery = false;

	/**
	 * @param boolean $isSubquery           whether or not this query object is a subquery of another
	 *                                      query object
	 */
	protected $_isSubquery;

	/**
	 * @var array $_neededTables            an array containing the needed table aliases
	 */
	protected $_neededTables = array();

	/**
	 * @var array $pendingSubqueries        SELECT part subqueries, these are called pending subqueries since
	 *                                      they cannot be parsed directly (some queries might be correlated)
	 */
	protected $_pendingSubqueries = array();

	/**
	 * @var array $_pendingFields           an array of pending fields (fields waiting to be parsed)
	 */
	protected $_pendingFields = array();

	/**
	 * @var array $_parsers                 an array of parser objects, each DQL query part has its own parser
	 */
	protected $_parsers = array();

	/**
	 * @var array $_pendingJoinConditions    an array containing pending joins
	 */
	protected $_pendingJoinConditions = array();

	/**
	 * @var array
	 */
	protected $_expressionMap = array();

	/**
	 * @var string $_sql            cached SQL query
	 */
	protected $_sql;

	/**
	 * create
	 * returns a new Doctrine_Query object
	 *
	 * @param Doctrine_Connection $conn  optional connection parameter
	 * @param string $class              Query class to instantiate
	 * @return Doctrine_Query
	 */
	public static function create($conn = null, $class = null)
	{
		if ( ! $class) {
			$class = Doctrine_Manager::getInstance()
			->getAttribute(Doctrine_Core::ATTR_QUERY_CLASS);
		}
		return new $class($conn);
	}

	/**
	 * Clears all the sql parts.
	 */
	protected function clear()
	{
		$this->_preQueried = false;
		$this->_pendingJoinConditions = array();
		$this->_state = self::STATE_DIRTY;
	}

	/**
	 * Resets the query to the state just after it has been instantiated.
	 */
	public function reset()
	{
		$this->_subqueryAliases = array();
		$this->_aggregateAliasMap = array();
		$this->_pendingAggregates = array();
		$this->_pendingSubqueries = array();
		$this->_pendingFields = array();
		$this->_neededTables = array();
		$this->_expressionMap = array();
		$this->_subqueryAliases = array();
		$this->_needsSubquery = false;
		$this->_isLimitSubqueryUsed = false;
	}

	/**
	 * createSubquery
	 * creates a subquery
	 *
	 * @return Doctrine_Hydrate
	 */
	public function createSubquery()
	{
		$class = get_class($this);
		$obj   = new $class();

		// copy the aliases to the subquery
		$obj->copySubqueryInfo($this);

		// this prevents the 'id' being selected, re ticket #307
		$obj->isSubquery(true);

		return $obj;
	}

	/**
	 * addPendingJoinCondition
	 *
	 * @param string $componentAlias    component alias
	 * @param string $joinCondition     dql join condition
	 * @return Doctrine_Query           this object
	 */
	public function addPendingJoinCondition($componentAlias, $joinCondition)
	{
		if ( ! isset($this->_pendingJoinConditions[$componentAlias])) {
			$this->_pendingJoinConditions[$componentAlias] = array();
		}

		$this->_pendingJoinConditions[$componentAlias][] = $joinCondition;
	}

	/**
	 * fetchArray
	 * Convenience method to execute using array fetching as hydration mode.
	 *
	 * @param string $params
	 * @return array
	 */
	public function fetchArray($params = array())
	{
		return $this->execute($params, Doctrine_Core::HYDRATE_ARRAY);
	}

	/**
	 * fetchOne
	 * Convenience method to execute the query and return the first item
	 * of the collection.
	 *
	 * @param string $params        Query parameters
	 * @param int $hydrationMode    Hydration mode: see Doctrine_Core::HYDRATE_* constants
	 * @return mixed                Array or Doctrine_Collection, depending on hydration mode. False if no result.
	 */
	public function fetchOne($params = array(), $hydrationMode = null)
	{
		$collection = $this->execute($params, $hydrationMode);

		if (is_scalar($collection)) {
			return $collection;
		}

		if (count($collection) === 0) {
			return false;
		}

		if ($collection instanceof Doctrine_Collection) {
			return $collection->getFirst();
		} else if (is_array($collection)) {
			return array_shift($collection);
		}

		return false;
	}

	/**
	 * isSubquery
	 * if $bool parameter is set this method sets the value of
	 * Doctrine_Query::$isSubquery. If this value is set to true
	 * the query object will not load the primary key fields of the selected
	 * components.
	 *
	 * If null is given as the first parameter this method retrieves the current
	 * value of Doctrine_Query::$isSubquery.
	 *
	 * @param boolean $bool     whether or not this query acts as a subquery
	 * @return Doctrine_Query|bool
	 */
	public function isSubquery($bool = null)
	{
		if ($bool === null) {
			return $this->_isSubquery;
		}

		$this->_isSubquery = (bool) $bool;
		return $this;
	}

	/**
	 * getSqlAggregateAlias
	 *
	 * @param string $dqlAlias      the dql alias of an aggregate value
	 * @return string
	 */
	public function getSqlAggregateAlias($dqlAlias)
	{
		if (isset($this->_aggregateAliasMap[$dqlAlias])) {
			// mark the expression as used
			$this->_expressionMap[$dqlAlias][1] = true;

			return $this->_aggregateAliasMap[$dqlAlias];
		} else if ( ! empty($this->_pendingAggregates)) {
			$this->processPendingAggregates();

			return $this->getSqlAggregateAlias($dqlAlias);
		} else if( ! ($this->_conn->getAttribute(Doctrine_Core::ATTR_PORTABILITY) & Doctrine_Core::PORTABILITY_EXPR)){
			return $dqlAlias;
		} else {
			throw new Doctrine_Query_Exception('Unknown aggregate alias: ' . $dqlAlias);
		}
	}

	/**
	 * Check if a dql alias has a sql aggregate alias
	 *
	 * @param string $dqlAlias
	 * @return boolean
	 */
	public function hasSqlAggregateAlias($dqlAlias)
	{
		try {
			$this->getSqlAggregateAlias($dqlAlias);
			return true;
		} catch (Exception $e) {
			return false;
		}
	}

	/**
	 * Adjust the processed param index for "foo.bar IN ?" support
	 *
	 */
	public function adjustProcessedParam($index)
	{
		// Retrieve all params
		$params = $this->getInternalParams();

		// Retrieve already processed values
		$first = array_slice($params, 0, $index);
		$last = array_slice($params, $index, count($params) - $index);

		// Include array as values splicing the params array
		array_splice($last, 0, 1, $last[0]);

		// Put all param values into a single index
		$this->_execParams = array_merge($first, $last);
	}

	/**
	 * Retrieves a specific DQL query part.
	 *
	 * @see Doctrine_Query_Abstract::$_dqlParts
	 * <code>
	 * var_dump($q->getDqlPart('where'));
	 * // array(2) { [0] => string(8) 'name = ?' [1] => string(8) 'date > ?' }
	 * </code>
	 * @param string $queryPart     the name of the query part; can be:
	 *     array from, containing strings;
	 *     array select, containg string;
	 *     boolean forUpdate;
	 *     array set;
	 *     array join;
	 *     array where;
	 *     array groupby;
	 *     array having;
	 *     array orderby, containing strings such as 'id ASC';
	 *     array limit, containing numerics;
	 *     array offset, containing numerics;
	 * @return array
	 */
	public function getDqlPart($queryPart)
	{
		if ( ! isset($this->_dqlParts[$queryPart])) {
			throw new Doctrine_Query_Exception('Unknown query part ' . $queryPart);
		}

		return $this->_dqlParts[$queryPart];
	}

	/**
	 * contains
	 *
	 * Method to check if a arbitrary piece of dql exists
	 *
	 * @param string $dql Arbitrary piece of dql to check for
	 * @return boolean
	 */
	public function contains($dql)
	{
		return stripos($this->getDql(), $dql) === false ? false : true;
	}

	/**
	 * processPendingFields
	 * the fields in SELECT clause cannot be parsed until the components
	 * in FROM clause are parsed, hence this method is called everytime a
	 * specific component is being parsed. For instance, the wildcard '*'
	 * is expanded in the list of columns.
	 *
	 * @throws Doctrine_Query_Exception     if unknown component alias has been given
	 * @param string $componentAlias        the alias of the component
	 * @return string SQL code
	 * @todo Description: What is a 'pending field' (and are there non-pending fields, too)?
	 *       What is 'processed'? (Meaning: What information is gathered & stored away)
	 */
	public function processPendingFields($componentAlias)
	{
		$tableAlias = $this->getSqlTableAlias($componentAlias);
		$table = $this->_queryComponents[$componentAlias]['table'];

		if ( ! isset($this->_pendingFields[$componentAlias])) {
			if ($this->_hydrator->getHydrationMode() != Doctrine_Core::HYDRATE_NONE) {
				if ( ! $this->_isSubquery && $componentAlias == $this->getRootAlias()) {
					throw new Doctrine_Query_Exception("The root class of the query (alias $componentAlias) "
					. " must have at least one field selected.");
				}
			}
			return;
		}

		// At this point we know the component is FETCHED (either it's the base class of
		// the query (FROM xyz) or its a "fetch join").

		// Check that the parent join (if there is one), is a "fetch join", too.
		if ( ! $this->isSubquery() && isset($this->_queryComponents[$componentAlias]['parent'])) {
			$parentAlias = $this->_queryComponents[$componentAlias]['parent'];
			if (is_string($parentAlias) && ! isset($this->_pendingFields[$parentAlias])
			&& $this->_hydrator->getHydrationMode() != Doctrine_Core::HYDRATE_NONE
			&& $this->_hydrator->getHydrationMode() != Doctrine_Core::HYDRATE_SCALAR
			&& $this->_hydrator->getHydrationMode() != Doctrine_Core::HYDRATE_SINGLE_SCALAR) {
				throw new Doctrine_Query_Exception("The left side of the join between "
				. "the aliases '$parentAlias' and '$componentAlias' must have at least"
				. " the primary key field(s) selected.");
			}
		}

		$fields = $this->_pendingFields[$componentAlias];

		// check for wildcards
		if (in_array('*', $fields)) {
			$fields = $table->getFieldNames();
		} else {
			$driverClassName = $this->_hydrator->getHydratorDriverClassName();
			// only auto-add the primary key fields if this query object is not
			// a subquery of another query object or we're using a child of the Object Graph
			// hydrator
			if ( ! $this->_isSubquery && is_subclass_of($driverClassName, 'Doctrine_Hydrator_Graph')) {
				$fields = array_unique(array_merge((array) $table->getIdentifier(), $fields));
			}
		}

		$sql = array();
		foreach ($fields as $fieldName) {
			$columnName = $table->getColumnName($fieldName);
			if (($owner = $table->getColumnOwner($columnName)) !== null &&
			$owner !== $table->getComponentName()) {

				$parent = $this->_conn->getTable($owner);
				$columnName = $parent->getColumnName($fieldName);
				$parentAlias = $this->getSqlTableAlias($componentAlias . '.' . $parent->getComponentName());
				$sql[] = $this->_conn->quoteIdentifier($parentAlias) . '.' . $this->_conn->quoteIdentifier($columnName)
				. ' AS '
				. $this->_conn->quoteIdentifier($tableAlias . '__' . $columnName);
			} else {
				$columnName = $table->getColumnName($fieldName);
				$sql[] = $this->_conn->quoteIdentifier($tableAlias) . '.' . $this->_conn->quoteIdentifier($columnName)
				. ' AS '
				. $this->_conn->quoteIdentifier($tableAlias . '__' . $columnName);
			}
		}

		$this->_neededTables[] = $tableAlias;

		return implode(', ', $sql);
	}

	/**
	 * Parses a nested field
	 * <code>
	 * $q->parseSelectField('u.Phonenumber.value');
	 * </code>
	 *
	 * @param string $field
	 * @throws Doctrine_Query_Exception     if unknown component alias has been given
	 * @return string   SQL fragment
	 * @todo Description: Explain what this method does. Is there a relation to parseSelect()?
	 *       This method is not used from any class or testcase in the Doctrine package.
	 *
	 */
	public function parseSelectField($field)
	{
		$terms = explode('.', $field);

		if (isset($terms[1])) {
			$componentAlias = $terms[0];
			$field = $terms[1];
		} else {
			reset($this->_queryComponents);
			$componentAlias = key($this->_queryComponents);
			$fields = $terms[0];
		}

		$tableAlias = $this->getSqlTableAlias($componentAlias);
		$table      = $this->_queryComponents[$componentAlias]['table'];


		// check for wildcards
		if ($field === '*') {
			$sql = array();

			foreach ($table->getColumnNames() as $field) {
				$sql[] = $this->parseSelectField($componentAlias . '.' . $field);
			}

			return implode(', ', $sql);
		} else {
			$name = $table->getColumnName($field);

			$this->_neededTables[] = $tableAlias;

			return $this->_conn->quoteIdentifier($tableAlias . '.' . $name)
			. ' AS '
			. $this->_conn->quoteIdentifier($tableAlias . '__' . $name);
		}
	}

	/**
	 * getExpressionOwner
	 * returns the component alias for owner of given expression
	 *
	 * @param string $expr      expression from which to get to owner from
	 * @return string           the component alias
	 * @todo Description: What does it mean if a component is an 'owner' of an expression?
	 *       What kind of 'expression' are we talking about here?
	 */
	public function getExpressionOwner($expr)
	{
		if (strtoupper(substr(trim($expr, '( '), 0, 6)) !== 'SELECT') {
			preg_match_all("/[a-z_][a-z0-9_]*\.[a-z_][a-z0-9_]*[\.[a-z0-9]+]*/i", $expr, $matches);

			$match = current($matches);

			if (isset($match[0])) {
				$terms = explode('.', $match[0]);

				return $terms[0];
			}
		}
		return $this->getRootAlias();

	}

	/**
	 * parseSelect
	 * parses the query select part and
	 * adds selected fields to pendingFields array
	 *
	 * @param string $dql
	 * @todo Description: What information is extracted (and then stored)?
	 */
	public function parseSelect($dql)
	{
		$refs = $this->_tokenizer->sqlExplode($dql, ',');

		$pos   = strpos(trim($refs[0]), ' ');
		$first = substr($refs[0], 0, $pos);

		// check for DISTINCT keyword
		if ($first === 'DISTINCT') {
			$this->_sqlParts['distinct'] = true;

			$refs[0] = substr($refs[0], ++$pos);
		}

		$parsedComponents = array();

		foreach ($refs as $reference) {
			$reference = trim($reference);

			if (empty($reference)) {
				continue;
			}

			$terms = $this->_tokenizer->sqlExplode($reference, ' ');

			$pos   = strpos($terms[0], '(');

			if (count($terms) > 1 || $pos !== false) {
				$expression = array_shift($terms);
				$alias = array_pop($terms);

				if ( ! $alias) {
					$alias = substr($expression, 0, $pos);
				}

				$componentAlias = $this->getExpressionOwner($expression);
				$expression = $this->parseClause($expression);

				$tableAlias = $this->getSqlTableAlias($componentAlias);

				$index    = count($this->_aggregateAliasMap);

				$sqlAlias = $this->_conn->quoteIdentifier($tableAlias . '__' . $index);

				$this->_sqlParts['select'][] = $expression . ' AS ' . $sqlAlias;

				$this->_aggregateAliasMap[$alias] = $sqlAlias;
				$this->_expressionMap[$alias][0] = $expression;

				$this->_queryComponents[$componentAlias]['agg'][$index] = $alias;

				$this->_neededTables[] = $tableAlias;
			} else {
				$e = explode('.', $terms[0]);

				if (isset($e[1])) {
					$componentAlias = $e[0];
					$field = $e[1];
				} else {
					reset($this->_queryComponents);
					$componentAlias = key($this->_queryComponents);
					$field = $e[0];
				}

				$this->_pendingFields[$componentAlias][] = $field;
			}
		}
	}

	/**
	 * parseClause
	 * parses given DQL clause
	 *
	 * this method handles five tasks:
	 *
	 * 1. Converts all DQL functions to their native SQL equivalents
	 * 2. Converts all component references to their table alias equivalents
	 * 3. Converts all field names to actual column names
	 * 4. Quotes all identifiers
	 * 5. Parses nested clauses and subqueries recursively
	 *
	 * @return string   SQL string
	 * @todo Description: What is a 'dql clause' (and what not)?
	 *       Refactor: Too long & nesting level
	 */
	public function parseClause($clause)
	{
		$clause = $this->_conn->dataDict->parseBoolean(trim($clause));

		if (is_numeric($clause)) {
			return $clause;
		}

		$terms = $this->_tokenizer->clauseExplode($clause, array(' ', '+', '-', '*', '/', '<', '>', '=', '>=', '<=', '&', '|'));
		$str = '';

		foreach ($terms as $term) {
			$pos = strpos($term[0], '(');

			if ($pos !== false && substr($term[0], 0, 1) !== "'") {
				$name = substr($term[0], 0, $pos);

				$term[0] = $this->parseFunctionExpression($term[0]);
			} else {
				if (substr($term[0], 0, 1) !== "'" && substr($term[0], -1) !== "'") {
					if (strpos($term[0], '.') !== false) {
						if ( ! is_numeric($term[0])) {
							$e = explode('.', $term[0]);

							$field = array_pop($e);

							if ($this->getType() === Doctrine_Query::SELECT) {
								$componentAlias = implode('.', $e);

								if (empty($componentAlias)) {
									$componentAlias = $this->getRootAlias();
								}

								$this->load($componentAlias);

								// check the existence of the component alias
								if ( ! isset($this->_queryComponents[$componentAlias])) {
									throw new Doctrine_Query_Exception('Unknown component alias ' . $componentAlias);
								}

								$table = $this->_queryComponents[$componentAlias]['table'];

								$def = $table->getDefinitionOf($field);

								// get the actual field name from alias
								$field = $table->getColumnName($field);

								// check column existence
								if ( ! $def) {
									throw new Doctrine_Query_Exception('Unknown column ' . $field);
								}

								if (isset($def['owner'])) {
									$componentAlias = $componentAlias . '.' . $def['owner'];
								}

								$tableAlias = $this->getSqlTableAlias($componentAlias);

								// build sql expression
								$term[0] = $this->_conn->quoteIdentifier($tableAlias)
								. '.'
								. $this->_conn->quoteIdentifier($field);
							} else {
								// build sql expression
								$field = $this->getRoot()->getColumnName($field);
								$term[0] = $this->_conn->quoteIdentifier($field);
							}
						}
					} else {
						if ( ! empty($term[0]) && ! in_array(strtoupper($term[0]), self::$_keywords) &&
						! is_numeric($term[0]) && $term[0] !== '?' && substr($term[0], 0, 1) !== ':') {

							$componentAlias = $this->getRootAlias();

							$found = false;

							if ($componentAlias !== false && $componentAlias !== null) {
								$table = $this->_queryComponents[$componentAlias]['table'];

								// check column existence
								if ($table->hasField($term[0])) {
									$found = true;

									$def = $table->getDefinitionOf($term[0]);

									// get the actual column name from field name
									$term[0] = $table->getColumnName($term[0]);


									if (isset($def['owner'])) {
										$componentAlias = $componentAlias . '.' . $def['owner'];
									}

									$tableAlias = $this->getSqlTableAlias($componentAlias);

									if ($this->getType() === Doctrine_Query::SELECT) {
										// build sql expression
										$term[0] = $this->_conn->quoteIdentifier($tableAlias)
										. '.'
										. $this->_conn->quoteIdentifier($term[0]);
									} else {
										// build sql expression
										$term[0] = $this->_conn->quoteIdentifier($term[0]);
									}
								} else {
									$found = false;
								}
							}

							if ( ! $found) {
								$term[0] = $this->getSqlAggregateAlias($term[0]);
							}
						}
					}
				}
			}

			$str .= $term[0] . $term[1];
		}
		return $str;
	}

	public function parseIdentifierReference($expr)
	{

	}

	public function parseFunctionExpression($expr)
	{
		$pos = strpos($expr, '(');
		$name = substr($expr, 0, $pos);

		if ($name === '') {
			return $this->parseSubquery($expr);
		}

		$argStr = substr($expr, ($pos + 1), -1);
		$args   = array();
		// parse args

		foreach ($this->_tokenizer->sqlExplode($argStr, ',') as $arg) {
			$args[] = $this->parseClause($arg);
		}

		// convert DQL function to its RDBMS specific equivalent
		try {
			$expr = call_user_func_array(array($this->_conn->expression, $name), $args);
		} catch (Doctrine_Expression_Exception $e) {
			throw new Doctrine_Query_Exception('Unknown function ' . $name . '.');
		}

		return $expr;
	}


	public function parseSubquery($subquery)
	{
		$trimmed = trim($this->_tokenizer->bracketTrim($subquery));

		// check for possible subqueries
		if (substr($trimmed, 0, 4) == 'FROM' || substr($trimmed, 0, 6) == 'SELECT') {
			// parse subquery
			$q = $this->createSubquery()->parseDqlQuery($trimmed);
			$trimmed = $q->getSqlQuery();
			$q->free();
		} else if (substr($trimmed, 0, 4) == 'SQL:') {
			$trimmed = substr($trimmed, 4);
		} else {
			$e = $this->_tokenizer->sqlExplode($trimmed, ',');

			$value = array();
			$index = false;

			foreach ($e as $part) {
				$value[] = $this->parseClause($part);
			}

			$trimmed = implode(', ', $value);
		}

		return '(' . $trimmed . ')';
	}


	/**
	 * processPendingSubqueries
	 * processes pending subqueries
	 *
	 * subqueries can only be processed when the query is fully constructed
	 * since some subqueries may be correlated
	 *
	 * @return void
	 * @todo Better description. i.e. What is a 'pending subquery'? What does 'processed' mean?
	 *       (parsed? sql is constructed? some information is gathered?)
	 */
	public function processPendingSubqueries()
	{
		foreach ($this->_pendingSubqueries as $value) {
			list($dql, $alias) = $value;

			$subquery = $this->createSubquery();

			$sql = $subquery->parseDqlQuery($dql, false)->getQuery();
			$subquery->free();

			reset($this->_queryComponents);
			$componentAlias = key($this->_queryComponents);
			$tableAlias = $this->getSqlTableAlias($componentAlias);

			$sqlAlias = $tableAlias . '__' . count($this->_aggregateAliasMap);

			$this->_sqlParts['select'][] = '(' . $sql . ') AS ' . $this->_conn->quoteIdentifier($sqlAlias);

			$this->_aggregateAliasMap[$alias] = $sqlAlias;
			$this->_queryComponents[$componentAlias]['agg'][] = $alias;
		}
		$this->_pendingSubqueries = array();
	}

	/**
	 * processPendingAggregates
	 * processes pending aggregate values for given component alias
	 *
	 * @return void
	 * @todo Better description. i.e. What is a 'pending aggregate'? What does 'processed' mean?
	 */
	public function processPendingAggregates()
	{
		// iterate trhough all aggregates
		foreach ($this->_pendingAggregates as $aggregate) {
			list ($expression, $components, $alias) = $aggregate;

			$tableAliases = array();

			// iterate through the component references within the aggregate function
			if ( ! empty ($components)) {
				foreach ($components as $component) {

					if (is_numeric($component)) {
						continue;
					}

					$e = explode('.', $component);

					$field = array_pop($e);
					$componentAlias = implode('.', $e);

					// check the existence of the component alias
					if ( ! isset($this->_queryComponents[$componentAlias])) {
						throw new Doctrine_Query_Exception('Unknown component alias ' . $componentAlias);
					}

					$table = $this->_queryComponents[$componentAlias]['table'];

					$field = $table->getColumnName($field);

					// check column existence
					if ( ! $table->hasColumn($field)) {
						throw new Doctrine_Query_Exception('Unknown column ' . $field);
					}

					$sqlTableAlias = $this->getSqlTableAlias($componentAlias);

					$tableAliases[$sqlTableAlias] = true;

					// build sql expression

					$identifier = $this->_conn->quoteIdentifier($sqlTableAlias . '.' . $field);
					$expression = str_replace($component, $identifier, $expression);
				}
			}

			if (count($tableAliases) !== 1) {
				$componentAlias = reset($this->_tableAliasMap);
				$tableAlias = key($this->_tableAliasMap);
			}

			$index    = count($this->_aggregateAliasMap);
			$sqlAlias = $this->_conn->quoteIdentifier($tableAlias . '__' . $index);

			$this->_sqlParts['select'][] = $expression . ' AS ' . $sqlAlias;

			$this->_aggregateAliasMap[$alias] = $sqlAlias;
			$this->_expressionMap[$alias][0] = $expression;

			$this->_queryComponents[$componentAlias]['agg'][$index] = $alias;

			$this->_neededTables[] = $tableAlias;
		}
		// reset the state
		$this->_pendingAggregates = array();
	}

	/**
	 * _buildSqlQueryBase
	 * returns the base of the generated sql query
	 * On mysql driver special strategy has to be used for DELETE statements
	 * (where is this special strategy??)
	 *
	 * @return string       the base of the generated sql query
	 */
	protected function _buildSqlQueryBase()
	{
		switch ($this->_type) {
			case self::DELETE:
				$q = 'DELETE FROM ';
				break;
			case self::UPDATE:
				$q = 'UPDATE ';
				break;
			case self::SELECT:
				$distinct = ($this->_sqlParts['distinct']) ? 'DISTINCT ' : '';
				$q = 'SELECT ' . $distinct . implode(', ', $this->_sqlParts['select']) . ' FROM ';
				break;
		}
		return $q;
	}

	/**
	 * _buildSqlFromPart
	 * builds the from part of the query and returns it
	 *
	 * @return string   the query sql from part
	 */
	protected function _buildSqlFromPart($ignorePending = false)
	{
		$q = '';

		foreach ($this->_sqlParts['from'] as $k => $part) {
			$e = explode(' ', $part);

			if ($k === 0) {
				if ( ! $ignorePending && $this->_type == self::SELECT) {
					// We may still have pending conditions
					$alias = count($e) > 1
					? $this->getComponentAlias($e[1])
					: null;
					$where = $this->_processPendingJoinConditions($alias);

					// apply inheritance to WHERE part
					if ( ! empty($where)) {
						if (count($this->_sqlParts['where']) > 0) {
							$this->_sqlParts['where'][] = 'AND';
						}

						if (substr($where, 0, 1) === '(' && substr($where, -1) === ')') {
							$this->_sqlParts['where'][] = $where;
						} else {
							$this->_sqlParts['where'][] = '(' . $where . ')';
						}
					}
				}

				$q .= $part;

				continue;
			}

			// preserve LEFT JOINs only if needed
			// Check if it's JOIN, if not add a comma separator instead of space
			if ( ! preg_match('/\bJOIN\b/i', $part) && ! isset($this->_pendingJoinConditions[$k])) {
				$q .= ', ' . $part;
			} else {
				if (substr($part, 0, 9) === 'LEFT JOIN') {
					$aliases = array_merge($this->_subqueryAliases,
					array_keys($this->_neededTables));

					if ( ! in_array($e[3], $aliases) && ! in_array($e[2], $aliases) && ! empty($this->_pendingFields)) {
						continue;
					}

				}

				if ( ! $ignorePending && isset($this->_pendingJoinConditions[$k])) {
					if (strpos($part, ' ON ') !== false) {
						$part .= ' AND ';
					} else {
						$part .= ' ON ';
					}

					$part .= $this->_processPendingJoinConditions($k);
				}

				$componentAlias = $this->getComponentAlias($e[3]);
				$string = $this->getInheritanceCondition($componentAlias);

				if ($string) {
					$part = $part . ' AND ' . $string;
				}
				$q .= ' ' . $part;
			}

			$this->_sqlParts['from'][$k] = $part;
		}
		return $q;
	}

	/**
	 * Processes the pending join conditions, used for dynamically add conditions
	 * to root component/joined components without interfering in the main dql
	 * handling.
	 *
	 * @param string $alias Component Alias
	 * @return Processed pending conditions
	 */
	protected function _processPendingJoinConditions($alias)
	{
		$parts = array();

		if ($alias !== null && isset($this->_pendingJoinConditions[$alias])) {
			$parser = new Doctrine_Query_JoinCondition($this, $this->_tokenizer);

			foreach ($this->_pendingJoinConditions[$alias] as $joinCondition) {
				$parts[] = $parser->parse($joinCondition);
			}

			// FIX #1860 and #1876: Cannot unset them, otherwise query cannot be reused later
			//unset($this->_pendingJoinConditions[$alias]);
		}

		return (count($parts) > 0 ? '(' . implode(') AND (', $parts) . ')' : '');
	}

	/**
	 * builds the sql query from the given parameters and applies things such as
	 * column aggregation inheritance and limit subqueries if needed
	 *
	 * @param array $params             an array of prepared statement params (needed only in mysql driver
	 *                                  when limit subquery algorithm is used)
	 * @param bool $limitSubquery Whether or not to try and apply the limit subquery algorithm
	 * @return string                   the built sql query
	 */
	public function getSqlQuery($params = array(), $limitSubquery = true)
	{
		// Assign building/execution specific params
		$this->_params['exec'] = $params;

		// Initialize prepared parameters array
		$this->_execParams = $this->getFlattenedParams();

		if ($this->_state !== self::STATE_DIRTY) {
			$this->fixArrayParameterValues($this->getInternalParams());

			// Return compiled SQL
			return $this->_sql;
		}
		return $this->buildSqlQuery($limitSubquery);
	}

	/**
	 * Build the SQL query from the DQL
	 *
	 * @param bool $limitSubquery Whether or not to try and apply the limit subquery algorithm
	 * @return string $sql The generated SQL string
	 */
	public function buildSqlQuery($limitSubquery = true)
	{
		// reset the state
		if ( ! $this->isSubquery()) {
			$this->_queryComponents = array();
			$this->_pendingAggregates = array();
			$this->_aggregateAliasMap = array();
		}

		$this->reset();

		// invoke the preQuery hook
		$this->_preQuery();

		// process the DQL parts => generate the SQL parts.
		// this will also populate the $_queryComponents.
		foreach ($this->_dqlParts as $queryPartName => $queryParts) {
			// If we are parsing FROM clause, we'll need to diff the queryComponents later
			if ($queryPartName == 'from') {
				// Pick queryComponents before processing
				$queryComponentsBefore = $this->getQueryComponents();
			}

			// FIX #1667: _sqlParts are cleaned inside _processDqlQueryPart.
			if ($queryPartName != 'forUpdate') {
				$this->_processDqlQueryPart($queryPartName, $queryParts);
			}

			// We need to define the root alias
			if ($queryPartName == 'from') {
				// Pick queryComponents aftr processing
				$queryComponentsAfter = $this->getQueryComponents();

				// Root alias is the key of difference of query components
				$diffQueryComponents = array_diff_key($queryComponentsAfter, $queryComponentsBefore);
				$this->_rootAlias = key($diffQueryComponents);
			}
		}
		$this->_state = self::STATE_CLEAN;

		// Proceed with the generated SQL
		if (empty($this->_sqlParts['from'])) {
			return false;
		}

		$needsSubQuery = false;
		$subquery = '';
		$map = $this->getRootDeclaration();
		$table = $map['table'];
		$rootAlias = $this->getRootAlias();

		if ( ! empty($this->_sqlParts['limit']) && $this->_needsSubquery &&
		$table->getAttribute(Doctrine_Core::ATTR_QUERY_LIMIT) == Doctrine_Core::LIMIT_RECORDS) {
			// We do not need a limit-subquery if DISTINCT is used
			// and the selected fields are either from the root component or from a localKey relation (hasOne)
			// (i.e. DQL: SELECT DISTINCT u.id FROM User u LEFT JOIN u.phonenumbers LIMIT 5).
			if(!$this->_sqlParts['distinct']) {
				$this->_isLimitSubqueryUsed = true;
				$needsSubQuery = true;
			} else {
				foreach( array_keys($this->_pendingFields) as $alias){
					//no subquery for root fields
					if($alias == $this->getRootAlias()){
						continue;
					}

					//no subquery for ONE relations
					if(isset($this->_queryComponents[$alias]['relation']) &&
					$this->_queryComponents[$alias]['relation']->getType() == Doctrine_Relation::ONE){
						continue;
					}

					$this->_isLimitSubqueryUsed = true;
					$needsSubQuery = true;
				}
			}
		}

		$sql = array();

		if ( ! empty($this->_pendingFields)) {
			foreach ($this->_queryComponents as $alias => $map) {
				$fieldSql = $this->processPendingFields($alias);
				if ( ! empty($fieldSql)) {
					$sql[] = $fieldSql;
				}
			}
		}

		if ( ! empty($sql)) {
			array_unshift($this->_sqlParts['select'], implode(', ', $sql));
		}

		$this->_pendingFields = array();

		// build the basic query
		$q  = $this->_buildSqlQueryBase();
		$q .= $this->_buildSqlFromPart();

		if ( ! empty($this->_sqlParts['set'])) {
			$q .= ' SET ' . implode(', ', $this->_sqlParts['set']);
		}

		$string = $this->getInheritanceCondition($this->getRootAlias());

		// apply inheritance to WHERE part
		if ( ! empty($string)) {
			if (count($this->_sqlParts['where']) > 0) {
				$this->_sqlParts['where'][] = 'AND';
			}

			if (substr($string, 0, 1) === '(' && substr($string, -1) === ')') {
				$this->_sqlParts['where'][] = $string;
			} else {
				$this->_sqlParts['where'][] = '(' . $string . ')';
			}
		}

		$modifyLimit = true;
		$limitSubquerySql = '';

		if ( ( ! empty($this->_sqlParts['limit']) || ! empty($this->_sqlParts['offset'])) && $needsSubQuery && $limitSubquery) {
			$subquery = $this->getLimitSubquery();

			// what about composite keys?
			$idColumnName = $table->getColumnName($table->getIdentifier());

			switch (strtolower($this->_conn->getDriverName())) {
				case 'mysql':
					$this->useQueryCache(false);

					// mysql doesn't support LIMIT in subqueries
					$list = $this->_conn->execute($subquery, $this->_execParams)->fetchAll(Doctrine_Core::FETCH_COLUMN);
					$subquery = implode(', ', array_map(array($this->_conn, 'quote'), $list));

					break;

				case 'pgsql':
					$subqueryAlias = $this->_conn->quoteIdentifier('doctrine_subquery_alias');

					// pgsql needs special nested LIMIT subquery
					$subquery = 'SELECT ' . $subqueryAlias . '.' . $this->_conn->quoteIdentifier($idColumnName)
					. ' FROM (' . $subquery . ') AS ' . $subqueryAlias;

					break;
			}

			$field = $this->getSqlTableAlias($rootAlias) . '.' . $idColumnName;

			// FIX #1868: If not ID under MySQL is found to be restricted, restrict pk column for null
			//            (which will lead to a return of 0 items)
			$limitSubquerySql = $this->_conn->quoteIdentifier($field)
			. (( ! empty($subquery)) ? ' IN (' . $subquery . ')' : ' IS NULL')
			. ((count($this->_sqlParts['where']) > 0) ? ' AND ' : '');

			$modifyLimit = false;
		}

		// FIX #DC-26: Include limitSubquerySql as major relevance in conditions
		$emptyWhere = empty($this->_sqlParts['where']);

		if ( ! ($emptyWhere && $limitSubquerySql == '')) {
			$where = implode(' ', $this->_sqlParts['where']);
			$where = ($where == '' || (substr($where, 0, 1) === '(' && substr($where, -1) === ')'))
			? $where : '(' . $where . ')';

			$q .= ' WHERE ' . $limitSubquerySql . $where;
			//   .  (($limitSubquerySql == '' && count($this->_sqlParts['where']) == 1) ? substr($where, 1, -1) : $where);
		}

		// Fix the orderbys so we only have one orderby per value
		foreach ($this->_sqlParts['orderby'] as $k => $orderBy) {
			$e = explode(', ', $orderBy);
			unset($this->_sqlParts['orderby'][$k]);
			foreach ($e as $v) {
				$this->_sqlParts['orderby'][] = $v;
			}
		}

		// Add the default orderBy statements defined in the relationships and table classes
		// Only do this for SELECT queries
		if ($this->_type === self::SELECT) {
			foreach ($this->_queryComponents as $alias => $map) {
				$sqlAlias = $this->getSqlTableAlias($alias);
				if (isset($map['relation'])) {
					$orderBy = $map['relation']->getOrderByStatement($sqlAlias, true);
					if ($orderBy == $map['relation']['orderBy']) {
						if (isset($map['ref'])) {
							$orderBy = $map['relation']['refTable']->processOrderBy($sqlAlias, $map['relation']['orderBy'], true);
						} else {
							$orderBy = null;
						}
					}
				} else {
					$orderBy = $map['table']->getOrderByStatement($sqlAlias, true);
				}

				if ($orderBy) {
					$e = explode(',', $orderBy);
					$e = array_map('trim', $e);
					foreach ($e as $v) {
						if ( ! in_array($v, $this->_sqlParts['orderby'])) {
							$this->_sqlParts['orderby'][] = $v;
						}
					}
				}
			}
		}

		$q .= ( ! empty($this->_sqlParts['groupby'])) ? ' GROUP BY ' . implode(', ', $this->_sqlParts['groupby'])  : '';
		$q .= ( ! empty($this->_sqlParts['having'])) ?  ' HAVING '   . implode(' AND ', $this->_sqlParts['having']): '';
		$q .= ( ! empty($this->_sqlParts['orderby'])) ? ' ORDER BY ' . implode(', ', $this->_sqlParts['orderby'])  : '';

		if ($modifyLimit) {
			$q = $this->_conn->modifyLimitQuery($q, $this->_sqlParts['limit'], $this->_sqlParts['offset']);
		}

		$q .= $this->_sqlParts['forUpdate'] === true ? ' FOR UPDATE ' : '';

		$this->_sql = $q;

		$this->clear();

		return $q;
	}

	/**
	 * getLimitSubquery
	 * this is method is used by the record limit algorithm
	 *
	 * when fetching one-to-many, many-to-many associated data with LIMIT clause
	 * an additional subquery is needed for limiting the number of returned records instead
	 * of limiting the number of sql result set rows
	 *
	 * @return string       the limit subquery
	 * @todo A little refactor to make the method easier to understand & maybe shorter?
	 */
	public function getLimitSubquery()
	{
		$map = reset($this->_queryComponents);
		$table = $map['table'];
		$componentAlias = key($this->_queryComponents);

		// get short alias
		$alias = $this->getSqlTableAlias($componentAlias);
		// what about composite keys?
		$primaryKey = $alias . '.' . $table->getColumnName($table->getIdentifier());

		$driverName = $this->_conn->getAttribute(Doctrine_Core::ATTR_DRIVER_NAME);

		// initialize the base of the subquery
		if (($driverName == 'oracle' || $driverName == 'oci') && $this->_isOrderedByJoinedColumn()) {
			$subquery = 'SELECT ';
		} else {
			$subquery = 'SELECT DISTINCT ';
		}
		$subquery .= $this->_conn->quoteIdentifier($primaryKey);

		// pgsql & oracle need the order by fields to be preserved in select clause
		if ($driverName == 'pgsql' || $driverName == 'oracle' || $driverName == 'oci' || $driverName == 'mssql' || $driverName == 'odbc') {
			foreach ($this->_sqlParts['orderby'] as $part) {
				// Remove identifier quoting if it exists
				$e = $this->_tokenizer->bracketExplode($part, ' ');
				foreach ($e as $f) {
					if ($f == 0 || $f % 2 == 0) {
						$partOriginal = str_replace(',', '', trim($f));
						$callback = create_function('$e', 'return trim($e, \'[]`"\');');
						$part = trim(implode('.', array_map($callback, explode('.', $partOriginal))));

						if (strpos($part, '.') === false) {
							continue;
						}

						// don't add functions
						if (strpos($part, '(') !== false) {
							continue;
						}

						// don't add primarykey column (its already in the select clause)
						if ($part !== $primaryKey) {
							$subquery .= ', ' . $partOriginal;
						}
					}
				}
			}
		}

		$orderby = $this->_sqlParts['orderby'];
		$having = $this->_sqlParts['having'];
		if ($driverName == 'mysql' || $driverName == 'pgsql') {
			foreach ($this->_expressionMap as $dqlAlias => $expr) {
				if (isset($expr[1])) {
					$subquery .= ', ' . $expr[0] . ' AS ' . $this->_aggregateAliasMap[$dqlAlias];
				}
			}
		} else {
			foreach ($this->_expressionMap as $dqlAlias => $expr) {
				if (isset($expr[1])) {
					foreach ($having as $k => $v) {
						$having[$k] = str_replace($this->_aggregateAliasMap[$dqlAlias], $expr[0], $v);
					}
					foreach ($orderby as $k => $v) {
						$e = explode(' ', $v);
						if ($e[0] == $this->_aggregateAliasMap[$dqlAlias]) {
							$orderby[$k] = $expr[0];
						}
					}
				}
			}
		}

		// Add having fields that got stripped out of select
		preg_match_all('/`[a-z0-9_]+`\.`[a-z0-9_]+`/i', implode(' ', $having), $matches, PREG_PATTERN_ORDER);
		if (count($matches[0]) > 0) {
			$subquery .= ', ' . implode(', ', array_unique($matches[0]));
		}

		$subquery .= ' FROM';

		foreach ($this->_sqlParts['from'] as $part) {
			// preserve LEFT JOINs only if needed
			if (substr($part, 0, 9) === 'LEFT JOIN') {
				$e = explode(' ', $part);

				if (empty($this->_sqlParts['orderby']) && empty($this->_sqlParts['where']) && empty($this->_sqlParts['having'])) {
					continue;
				}
			}

			$subquery .= ' ' . $part;
		}

		// all conditions must be preserved in subquery
		$subquery .= ( ! empty($this->_sqlParts['where']))?   ' WHERE '    . implode(' ', $this->_sqlParts['where'])  : '';
		$subquery .= ( ! empty($this->_sqlParts['groupby']))? ' GROUP BY ' . implode(', ', $this->_sqlParts['groupby'])   : '';
		$subquery .= ( ! empty($having))?  ' HAVING '   . implode(' AND ', $having) : '';
		$subquery .= ( ! empty($orderby))? ' ORDER BY ' . implode(', ', $orderby)  : '';

		if (($driverName == 'oracle' || $driverName == 'oci') && $this->_isOrderedByJoinedColumn()) {
			// When using "ORDER BY x.foo" where x.foo is a column of a joined table,
			// we may get duplicate primary keys because all columns in ORDER BY must appear
			// in the SELECT list when using DISTINCT. Hence we need to filter out the
			// primary keys with an additional DISTINCT subquery.
			// #1038
			$quotedIdentifierColumnName = $this->_conn->quoteIdentifier($table->getColumnName($table->getIdentifier()));
			$subquery = 'SELECT doctrine_subquery_alias.' . $quotedIdentifierColumnName
			. ' FROM (' . $subquery . ') doctrine_subquery_alias'
			. ' GROUP BY doctrine_subquery_alias.' . $quotedIdentifierColumnName
			. ' ORDER BY MIN(ROWNUM)';
		}

		// add driver specific limit clause
		$subquery = $this->_conn->modifyLimitSubquery($table, $subquery, $this->_sqlParts['limit'], $this->_sqlParts['offset']);

		$parts = $this->_tokenizer->quoteExplode($subquery, ' ', "'", "'");

		foreach ($parts as $k => $part) {
			if (strpos($part, ' ') !== false) {
				continue;
			}

			$part = str_replace(array('"', "'", '`'), "", $part);

			if ($this->hasSqlTableAlias($part)) {
				$parts[$k] = $this->_conn->quoteIdentifier($this->generateNewSqlTableAlias($part));
				continue;
			}

			if (strpos($part, '.') === false) {
				continue;
			}

			preg_match_all("/[a-zA-Z0-9_]+\.[a-z0-9_]+/i", $part, $m);

			foreach ($m[0] as $match) {
				$e = explode('.', $match);

				// Rebuild the original part without the newly generate alias and with quoting reapplied
				$e2 = array();
				foreach ($e as $k2 => $v2) {
					$e2[$k2] = $this->_conn->quoteIdentifier($v2);
				}
				$match = implode('.', $e2);

				// Generate new table alias
				$e[0] = $this->generateNewSqlTableAlias($e[0]);

				// Requote the part with the newly generated alias
				foreach ($e as $k2 => $v2) {
					$e[$k2] = $this->_conn->quoteIdentifier($v2);
				}

				$replace = implode('.' , $e);

				// Replace the original part with the new part with new sql table alias
				$parts[$k] = str_replace($match, $replace, $parts[$k]);
			}
		}

		if ($driverName == 'mysql' || $driverName == 'pgsql') {
			foreach ($parts as $k => $part) {
				if (strpos($part, "'") !== false) {
					continue;
				}
				if (strpos($part, '__') == false) {
					continue;
				}

				preg_match_all("/[a-zA-Z0-9_]+\_\_[a-z0-9_]+/i", $part, $m);

				foreach ($m[0] as $match) {
					$e = explode('__', $match);
					$e[0] = $this->generateNewSqlTableAlias($e[0]);

					$parts[$k] = str_replace($match, implode('__', $e), $parts[$k]);
				}
			}
		}

		$subquery = implode(' ', $parts);
		return $subquery;
	}

	/**
	 * Checks whether the query has an ORDER BY on a column of a joined table.
	 * This information is needed in special scenarios like the limit-offset when its
	 * used with an Oracle database.
	 *
	 * @return boolean  TRUE if the query is ordered by a joined column, FALSE otherwise.
	 */
	private function _isOrderedByJoinedColumn() {
		if ( ! $this->_queryComponents) {
			throw new Doctrine_Query_Exception("The query is in an invalid state for this "
			. "operation. It must have been fully parsed first.");
		}
		$componentAlias = key($this->_queryComponents);
		$mainTableAlias = $this->getSqlTableAlias($componentAlias);
		foreach ($this->_sqlParts['orderby'] as $part) {
			$part = trim($part);
			$e = $this->_tokenizer->bracketExplode($part, ' ');
			$part = trim($e[0]);
			if (strpos($part, '.') === false) {
				continue;
			}
			list($tableAlias, $columnName) = explode('.', $part);
			if ($tableAlias != $mainTableAlias) {
				return true;
			}
		}
		return false;
	}

	/**
	 * DQL PARSER
	 * parses a DQL query
	 * first splits the query in parts and then uses individual
	 * parsers for each part
	 *
	 * @param string $query                 DQL query
	 * @param boolean $clear                whether or not to clear the aliases
	 * @throws Doctrine_Query_Exception     if some generic parsing error occurs
	 * @return Doctrine_Query
	 */
	public function parseDqlQuery($query, $clear = true)
	{
		if ($clear) {
			$this->clear();
		}

		$query = trim($query);
		$query = str_replace("\r", "\n", str_replace("\r\n", "\n", $query));
		$query = str_replace("\n", ' ', $query);

		$parts = $this->_tokenizer->tokenizeQuery($query);

		foreach ($parts as $partName => $subParts) {
			$subParts = trim($subParts);
			$partName = strtolower($partName);
			switch ($partName) {
				case 'create':
					$this->_type = self::CREATE;
					break;
				case 'insert':
					$this->_type = self::INSERT;
					break;
				case 'delete':
					$this->_type = self::DELETE;
					break;
				case 'select':
					$this->_type = self::SELECT;
					$this->_addDqlQueryPart($partName, $subParts);
					break;
				case 'update':
					$this->_type = self::UPDATE;
					$partName = 'from';
				case 'from':
					$this->_addDqlQueryPart($partName, $subParts);
					break;
				case 'set':
					$this->_addDqlQueryPart($partName, $subParts, true);
					break;
				case 'group':
				case 'order':
					$partName .= 'by';
				case 'where':
				case 'having':
				case 'limit':
				case 'offset':
					$this->_addDqlQueryPart($partName, $subParts);
					break;
			}
		}

		return $this;
	}

	/**
	 * @todo Describe & refactor... too long and nested.
	 * @param string $path          component alias
	 * @param boolean $loadFields
	 */
	public function load($path, $loadFields = true)
	{
		if (isset($this->_queryComponents[$path])) {
			return $this->_queryComponents[$path];
		}

		$e = $this->_tokenizer->quoteExplode($path, ' INDEXBY ');

		$mapWith = null;
		if (count($e) > 1) {
			$mapWith = trim($e[1]);

			$path = $e[0];
		}

		// parse custom join conditions
		$e = explode(' ON ', str_ireplace(' on ', ' ON ', $path));

		$joinCondition = '';

		if (count($e) > 1) {
			$joinCondition = substr($path, strlen($e[0]) + 4, strlen($e[1]));
			$path = substr($path, 0, strlen($e[0]));

			$overrideJoin = true;
		} else {
			$e = explode(' WITH ', str_ireplace(' with ', ' WITH ', $path));

			if (count($e) > 1) {
				$joinCondition = substr($path, strlen($e[0]) + 6, strlen($e[1]));
				$path = substr($path, 0, strlen($e[0]));
			}

			$overrideJoin = false;
		}

		$tmp            = explode(' ', $path);
		$componentAlias = $originalAlias = (count($tmp) > 1) ? end($tmp) : null;

		$e = preg_split("/[.:]/", $tmp[0], -1);

		$fullPath = $tmp[0];
		$prevPath = '';
		$fullLength = strlen($fullPath);

		if (isset($this->_queryComponents[$e[0]])) {
			$table = $this->_queryComponents[$e[0]]['table'];
			$componentAlias = $e[0];

			$prevPath = $parent = array_shift($e);
		}

		foreach ($e as $key => $name) {
			// get length of the previous path
			$length = strlen($prevPath);

			// build the current component path
			$prevPath = ($prevPath) ? $prevPath . '.' . $name : $name;

			$delimeter = substr($fullPath, $length, 1);

			// if an alias is not given use the current path as an alias identifier
			if (strlen($prevPath) === $fullLength && isset($originalAlias)) {
				$componentAlias = $originalAlias;
			} else {
				$componentAlias = $prevPath;
			}

			// if the current alias already exists, skip it
			if (isset($this->_queryComponents[$componentAlias])) {
				throw new Doctrine_Query_Exception("Duplicate alias '$componentAlias' in query.");
			}

			if ( ! isset($table)) {
				// process the root of the path

				$table = $this->loadRoot($name, $componentAlias);
			} else {
				$join = ($delimeter == ':') ? 'INNER JOIN ' : 'LEFT JOIN ';

				$relation = $table->getRelation($name);
				$localTable = $table;

				$table = $relation->getTable();
				$this->_queryComponents[$componentAlias] = array('table' => $table,
                                                                 'parent'   => $parent,
                                                                 'relation' => $relation,
                                                                 'map'      => null);
				if ( ! $relation->isOneToOne()) {
					$this->_needsSubquery = true;
				}

				$localAlias   = $this->getSqlTableAlias($parent, $localTable->getTableName());
				$foreignAlias = $this->getSqlTableAlias($componentAlias, $relation->getTable()->getTableName());

				$foreignSql   = $this->_conn->quoteIdentifier($relation->getTable()->getTableName())
				. ' '
				. $this->_conn->quoteIdentifier($foreignAlias);

				$map = $relation->getTable()->inheritanceMap;

				if ( ! $loadFields || ! empty($map) || $joinCondition) {
					$this->_subqueryAliases[] = $foreignAlias;
				}

				if ($relation instanceof Doctrine_Relation_Association) {
					$asf = $relation->getAssociationTable();

					$assocTableName = $asf->getTableName();

					if ( ! $loadFields || ! empty($map) || $joinCondition) {
						$this->_subqueryAliases[] = $assocTableName;
					}

					$assocPath = $prevPath . '.' . $asf->getComponentName() . ' ' . $componentAlias;

					$this->_queryComponents[$assocPath] = array(
                        'parent' => $prevPath,
                        'relation' => $relation,
                        'table' => $asf,
                        'ref' => true);

					$assocAlias = $this->getSqlTableAlias($assocPath, $asf->getTableName());

					$queryPart = $join
					. $this->_conn->quoteIdentifier($assocTableName)
					. ' '
					. $this->_conn->quoteIdentifier($assocAlias);

					$queryPart .= ' ON (' . $this->_conn->quoteIdentifier($localAlias
					. '.'
					. $localTable->getColumnName($localTable->getIdentifier())) // what about composite keys?
					. ' = '
					. $this->_conn->quoteIdentifier($assocAlias . '.' . $relation->getLocalRefColumnName());

					if ($relation->isEqual()) {
						// equal nest relation needs additional condition
						$queryPart .= ' OR '
						. $this->_conn->quoteIdentifier($localAlias
						. '.'
						. $table->getColumnName($table->getIdentifier()))
						. ' = '
						. $this->_conn->quoteIdentifier($assocAlias . '.' . $relation->getForeignRefColumnName());
					}

					$queryPart .= ')';

					$this->_sqlParts['from'][] = $queryPart;

					$queryPart = $join . $foreignSql;

					if ( ! $overrideJoin) {
						$queryPart .= $this->buildAssociativeRelationSql($relation, $assocAlias, $foreignAlias, $localAlias);
					}
				} else {
					$queryPart = $this->buildSimpleRelationSql($relation, $foreignAlias, $localAlias, $overrideJoin, $join);
				}

				$queryPart .= $this->buildInheritanceJoinSql($table->getComponentName(), $componentAlias);
				$this->_sqlParts['from'][$componentAlias] = $queryPart;

				if ( ! empty($joinCondition)) {
					$this->addPendingJoinCondition($componentAlias, $joinCondition);
				}
			}

			if ($loadFields) {
				$restoreState = false;

				// load fields if necessary
				if ($loadFields && empty($this->_dqlParts['select'])) {
					$this->_pendingFields[$componentAlias] = array('*');
				}
			}

			$parent = $prevPath;
		}

		$table = $this->_queryComponents[$componentAlias]['table'];

		return $this->buildIndexBy($componentAlias, $mapWith);
	}

	protected function buildSimpleRelationSql(Doctrine_Relation $relation, $foreignAlias, $localAlias, $overrideJoin, $join)
	{
		$queryPart = $join . $this->_conn->quoteIdentifier($relation->getTable()->getTableName())
		. ' '
		. $this->_conn->quoteIdentifier($foreignAlias);

		if ( ! $overrideJoin) {
			$queryPart .= ' ON '
			. $this->_conn->quoteIdentifier($localAlias . '.' . $relation->getLocalColumnName())
			. ' = '
			. $this->_conn->quoteIdentifier($foreignAlias . '.' . $relation->getForeignColumnName());
		}

		return $queryPart;
	}

	protected function buildIndexBy($componentAlias, $mapWith = null)
	{
		$table = $this->_queryComponents[$componentAlias]['table'];

		$indexBy = null;
		$column = false;

		if (isset($mapWith)) {
			$terms = explode('.', $mapWith);

			if (count($terms) == 1) {
				$indexBy = $terms[0];
			} else if (count($terms) == 2) {
				$column = true;
				$indexBy = $terms[1];
			}
		} else if ($table->getBoundQueryPart('indexBy') !== null) {
			$indexBy = $table->getBoundQueryPart('indexBy');
		}

		if ($indexBy !== null) {
			if ( $column && ! $table->hasColumn($table->getColumnName($indexBy))) {
				throw new Doctrine_Query_Exception("Couldn't use key mapping. Column " . $indexBy . " does not exist.");
			}

			$this->_queryComponents[$componentAlias]['map'] = $indexBy;
		}

		return $this->_queryComponents[$componentAlias];
	}


	protected function buildAssociativeRelationSql(Doctrine_Relation $relation, $assocAlias, $foreignAlias, $localAlias)
	{
		$table = $relation->getTable();

		$queryPart = ' ON ';

		if ($relation->isEqual()) {
			$queryPart .= '(';
		}

		$localIdentifier = $table->getColumnName($table->getIdentifier());

		$queryPart .= $this->_conn->quoteIdentifier($foreignAlias . '.' . $localIdentifier)
		. ' = '
		. $this->_conn->quoteIdentifier($assocAlias . '.' . $relation->getForeignRefColumnName());

		if ($relation->isEqual()) {
			$queryPart .= ' OR '
			. $this->_conn->quoteIdentifier($foreignAlias . '.' . $localIdentifier)
			. ' = '
			. $this->_conn->quoteIdentifier($assocAlias . '.' . $relation->getLocalRefColumnName())
			. ') AND '
			. $this->_conn->quoteIdentifier($foreignAlias . '.' . $localIdentifier)
			. ' != '
			. $this->_conn->quoteIdentifier($localAlias . '.' . $localIdentifier);
		}

		return $queryPart;
	}

	/**
	 * loadRoot
	 *
	 * @param string $name
	 * @param string $componentAlias
	 * @return Doctrine_Table
	 * @todo DESCRIBE ME!
	 * @todo this method is called only in Doctrine_Query class. Shouldn't be private or protected?
	 */
	public function loadRoot($name, $componentAlias)
	{
		// get the connection for the component
		$manager = Doctrine_Manager::getInstance();
		if ( ! $this->_passedConn && $manager->hasConnectionForComponent($name)) {
			$this->_conn = $manager->getConnectionForComponent($name);
		}

		$table = $this->_conn->getTable($name);
		$tableName = $table->getTableName();

		// get the short alias for this table
		$tableAlias = $this->getSqlTableAlias($componentAlias, $tableName);
		// quote table name
		$queryPart = $this->_conn->quoteIdentifier($tableName);

		if ($this->_type === self::SELECT) {
			$queryPart .= ' ' . $this->_conn->quoteIdentifier($tableAlias);
		}

		$this->_tableAliasMap[$tableAlias] = $componentAlias;

		$queryPart .= $this->buildInheritanceJoinSql($name, $componentAlias);

		$this->_sqlParts['from'][] = $queryPart;

		$this->_queryComponents[$componentAlias] = array('table' => $table, 'map' => null);

		return $table;
	}

	/**
	 * @todo DESCRIBE ME!
	 * @param string $name              component class name
	 * @param string $componentAlias    alias of the component in the dql
	 * @return string                   query part
	 */
	public function buildInheritanceJoinSql($name, $componentAlias)
	{
		// get the connection for the component
		$manager = Doctrine_Manager::getInstance();
		if ( ! $this->_passedConn && $manager->hasConnectionForComponent($name)) {
			$this->_conn = $manager->getConnectionForComponent($name);
		}

		$table = $this->_conn->getTable($name);
		$tableName = $table->getTableName();

		// get the short alias for this table
		$tableAlias = $this->getSqlTableAlias($componentAlias, $tableName);

		$queryPart = '';

		foreach ($table->getOption('joinedParents') as $parent) {
			$parentTable = $this->_conn->getTable($parent);

			$parentAlias = $componentAlias . '.' . $parent;

			// get the short alias for the parent table
			$parentTableAlias = $this->getSqlTableAlias($parentAlias, $parentTable->getTableName());

			$queryPart .= ' LEFT JOIN ' . $this->_conn->quoteIdentifier($parentTable->getTableName())
			. ' ' . $this->_conn->quoteIdentifier($parentTableAlias) . ' ON ';

			//Doctrine_Core::dump($table->getIdentifier());
			foreach ((array) $table->getIdentifier() as $identifier) {
				$column = $table->getColumnName($identifier);

				$queryPart .= $this->_conn->quoteIdentifier($tableAlias)
				. '.' . $this->_conn->quoteIdentifier($column)
				. ' = ' . $this->_conn->quoteIdentifier($parentTableAlias)
				. '.' . $this->_conn->quoteIdentifier($column);
			}
		}

		return $queryPart;
	}

	/**
	 * Get count sql query for this Doctrine_Query instance.
	 *
	 * This method is used in Doctrine_Query::count() for returning an integer
	 * for the number of records which will be returned when executed.
	 *
	 * @return string $q
	 */
	public function getCountSqlQuery()
	{
		// triggers dql parsing/processing
		$this->getSqlQuery(array(), false); // this is ugly

		// initialize temporary variables
		$where   = $this->_sqlParts['where'];
		$having  = $this->_sqlParts['having'];
		$groupby = $this->_sqlParts['groupby'];

		$rootAlias = $this->getRootAlias();
		$tableAlias = $this->getSqlTableAlias($rootAlias);

		// Build the query base
		$q = 'SELECT COUNT(*) AS ' . $this->_conn->quoteIdentifier('num_results') . ' FROM ';

		// Build the from clause
		$from = $this->_buildSqlFromPart(true);

		// Build the where clause
		$where = ( ! empty($where)) ? ' WHERE ' . implode(' ', $where) : '';

		// Build the group by clause
		$groupby = ( ! empty($groupby)) ? ' GROUP BY ' . implode(', ', $groupby) : '';

		// Build the having clause
		$having = ( ! empty($having)) ? ' HAVING ' . implode(' AND ', $having) : '';

		// Building the from clause and finishing query
		if (count($this->_queryComponents) == 1 && empty($having)) {
			$q .= $from . $where . $groupby . $having;
		} else {
			// Subselect fields will contain only the pk of root entity
			$ta = $this->_conn->quoteIdentifier($tableAlias);

			$map = $this->getRootDeclaration();
			$idColumnNames = $map['table']->getIdentifierColumnNames();

			$pkFields = $ta . '.' . implode(', ' . $ta . '.', $this->_conn->quoteMultipleIdentifier($idColumnNames));

			// We need to do some magic in select fields if the query contain anything in having clause
			$selectFields = $pkFields;

			if ( ! empty($having)) {
				// For each field defined in select clause
				foreach ($this->_sqlParts['select'] as $field) {
					// We only include aggregate expressions to count query
					// This is needed because HAVING clause will use field aliases
					if (strpos($field, '(') !== false) {
						$selectFields .= ', ' . $field;
					}
				}
				// Add having fields that got stripped out of select
				preg_match_all('/`[a-z0-9_]+`\.`[a-z0-9_]+`/i', $having, $matches, PREG_PATTERN_ORDER);
				if (count($matches[0]) > 0) {
					$selectFields .= ', ' . implode(', ', array_unique($matches[0]));
				}
			}

			// If we do not have a custom group by, apply the default one
			if (empty($groupby)) {
				$groupby = ' GROUP BY ' . $pkFields;
			}

			$q .= '(SELECT ' . $selectFields . ' FROM ' . $from . $where . $groupby . $having . ') '
			. $this->_conn->quoteIdentifier('dctrn_count_query');
		}

		return $q;
	}

	/**
	 * Fetches the count of the query.
	 *
	 * This method executes the main query without all the
	 * selected fields, ORDER BY part, LIMIT part and OFFSET part.
	 *
	 * Example:
	 * Main query:
	 *      SELECT u.*, p.phonenumber FROM User u
	 *          LEFT JOIN u.Phonenumber p
	 *          WHERE p.phonenumber = '123 123' LIMIT 10
	 *
	 * The modified DQL query:
	 *      SELECT COUNT(DISTINCT u.id) FROM User u
	 *          LEFT JOIN u.Phonenumber p
	 *          WHERE p.phonenumber = '123 123'
	 *
	 * @param array $params        an array of prepared statement parameters
	 * @return integer             the count of this query
	 */
	public function count($params = array())
	{
		$q = $this->getCountSqlQuery();
		$params = $this->getCountQueryParams($params);
		$params = $this->_conn->convertBooleans($params);

		if ($this->_resultCache) {
			$conn = $this->getConnection();
			$cacheDriver = $this->getResultCacheDriver();
			$hash = $this->getResultCacheHash($params).'_count';
			$cached = ($this->_expireResultCache) ? false : $cacheDriver->fetch($hash);

			if ($cached === false) {
				// cache miss
				$results = $this->getConnection()->fetchAll($q, $params);
				$cacheDriver->save($hash, serialize($results), $this->getResultCacheLifeSpan());
			} else {
				$results = unserialize($cached);
			}
		} else {
			$results = $this->getConnection()->fetchAll($q, $params);
		}

		if (count($results) > 1) {
			$count = count($results);
		} else {
			if (isset($results[0])) {
				$results[0] = array_change_key_case($results[0], CASE_LOWER);
				$count = $results[0]['num_results'];
			} else {
				$count = 0;
			}
		}

		return (int) $count;
	}

	/**
	 * Queries the database with DQL (Doctrine Query Language).
	 *
	 * This methods parses a Dql query and builds the query parts.
	 *
	 * @param string $query      Dql query
	 * @param array $params      prepared statement parameters
	 * @param int $hydrationMode Doctrine_Core::HYDRATE_ARRAY or Doctrine_Core::HYDRATE_RECORD
	 * @see Doctrine_Core::FETCH_* constants
	 * @return mixed
	 */
	public function query($query, $params = array(), $hydrationMode = null)
	{
		$this->parseDqlQuery($query);
		return $this->execute($params, $hydrationMode);
	}

	/**
	 * Copies a Doctrine_Query object.
	 *
	 * @return Doctrine_Query  Copy of the Doctrine_Query instance.
	 */
	public function copy(Doctrine_Query $query = null)
	{
		if ( ! $query) {
			$query = $this;
		}

		$new = clone $query;

		return $new;
	}

	/**
	 * Magic method called after cloning process.
	 *
	 * @return void
	 */
	public function __clone()
	{
		$this->_parsers = array();
		$this->_hydrator = clone $this->_hydrator;

		// Subqueries share some information from the parent so it can intermingle
		// with the dql of the main query. So when a subquery is cloned we need to
		// kill those references or it causes problems
		if ($this->isSubquery()) {
			$this->_killReference('_params');
			$this->_killReference('_tableAliasMap');
			$this->_killReference('_queryComponents');
		}
	}

	/**
	 * Kill the reference for the passed class property.
	 * This method simply copies the value to a temporary variable and then unsets
	 * the reference and re-assigns the old value but not by reference
	 *
	 * @param string $key
	 */
	protected function _killReference($key)
	{
		$tmp = $this->$key;
		unset($this->$key);
		$this->$key = $tmp;
	}

	/**
	 * Frees the resources used by the query object. It especially breaks a
	 * cyclic reference between the query object and it's parsers. This enables
	 * PHP's current GC to reclaim the memory.
	 * This method can therefore be used to reduce memory usage when creating
	 * a lot of query objects during a request.
	 *
	 * @return Doctrine_Query   this object
	 */
	public function free()
	{
		$this->reset();
		$this->_parsers = array();
		$this->_dqlParts = array();
	}
}